What is the clinical evidence from this study?

Study design: Observational. Population: Ischemic stroke (n=911). Intervention: Apnoea-hypopnoea index ≥ 15 and high hypoxic burden vs. Low apnoea-hypopnoea index and low hypoxic burden. Primary outcome: Atrial fibrillation (OR 1.97, 95% CI 1.25-3.12).

What question did this study set out to answer?

This study aims to evaluate if combining the apnoea–hypopnoea index and hypoxic burden enhances risk stratification for atrial fibrillation in stroke patients.

April 28, 2026Open Access

Enhanced Risk Stratification of Atrial Fibrillation Detected After Ischemic Stroke and TIA : The Role of Apnoea–Hypopnoea Index and Hypoxic Burden—A Study From the Bern Sleep‐Stroke Registry

Q: What does this research mean for the field?

Patients with ischemic stroke who have both an apnoea-hypopnoea index ≥15 and a high hypoxic burden have nearly double the odds of atrial fibrillation compared to those with low metrics. Novelty: ClaimNovelty.INCREMENTAL. Consensus alignment: ConsensusAlignment.NEUTRAL.

Key Result

Patients with ischemic stroke who had both an apnoea-hypopnoea index ≥15 and high hypoxic burden had nearly double the odds of atrial fibrillation (adjusted OR 1.97; 95% CI 1.25-3.12).

Key Points

This study aims to evaluate if combining the apnoea–hypopnoea index and hypoxic burden enhances risk stratification for atrial fibrillation in stroke patients.
911 patients with ischemic stroke underwent respiratory polygraphy within 3 days after an event.
Atrial fibrillation was monitored with three 7-day ECG recordings within 6 months.
Logistic regression assessed the association between apnoea-hypopnoea index, hypoxic burden, and atrial fibrillation.
Atrial fibrillation was detected in 145 (16%) of 911 patients.
Patients with both apnoea-hypopnoea index ≥ 15 and high hypoxic burden had adjusted odds ratio of 1.97 (95% CI 1.25–3.12) for atrial fibrillation.
Elevated apnoea-hypopnoea index and hypoxic burden together identified higher-risk stroke patients for atrial fibrillation.

Study Design

Type

Observational (n=911)

Structured PICO

Does the combination of elevated apnoea–hypopnoea index and high hypoxic burden predict atrial fibrillation detection in patients with recent ischemic stroke?

Population

911 patients with ischemic stroke who underwent respiratory polygraphy within 3 days after an event, mean age 66 ± 14 years, 62% male.

Intervention

High apnoea–hypopnoea index (≥ 15 events/h) combined with high hypoxic burden (above median, 35% min h⁻¹)

Comparator

Low apnoea–hypopnoea index (< 15 events/h) and low hypoxic burden

Outcome

Detection of atrial fibrillation within 6 monthshard clinical

Combining apnoea–hypopnoea index and hypoxic burden improves risk stratification for detecting atrial fibrillation after ischemic stroke.

Main Result

Effect estimate: OR 1.97 (95% CI 1.25-3.12)

Abstract

ABSTRACT Sleep‐disordered breathing is an independent risk factor for stroke and atrial fibrillation. Accurate assessment of atrial fibrillation in stroke patients with sleep‐disordered breathing is crucial for secondary prevention. This study aimed to determine whether combining apnoea–hypopnoea index and hypoxic burden improves risk stratification for atrial fibrillation detected after ischemic stroke. About 911 patients with ischemic stroke underwent respiratory polygraphy within 3 days after an event. Hypoxic burden was defined as the cumulative area under the oxygen desaturation curve of respiratory events. Atrial fibrillation was monitored with up to three 7‐day electrocardiogram recordings within 6 months. Patients were stratified by apnoea–hypopnoea index (≥ 15 vs. < 15 events/h) and by hypoxic burden (above vs. below the median, 35% min h −1 ). Logistic regression adjusted for age, sex, and cardiovascular risk factors assessed associations between apnoea–hypopnoea index/hypoxic burden categories and atrial fibrillation. Among 911 patients (mean age 66 ± 14 years, 62% male), atrial fibrillation was detected in 145 (16%) patients. Patients with both apnoea–hypopnoea index ≥ 15 and high hypoxic burden had nearly double the odds of atrial fibrillation compared to those with low apnoea–hypopnoea index and low hypoxic burden (adjusted odds ratio 1.97, 95% CI 1.25–3.12). In contrast, neither elevated apnoea–hypopnoea index nor high hypoxic burden alone demonstrated a statistically significant association. Elevated apnoea–hypopnoea index combined with high hypoxic burden identifies stroke patients at higher risk of atrial fibrillation. Integrating these metrics into post‐stroke evaluation may improve personalized management and secondary prevention of recurrent cardiovascular or cerebrovascular events.